#!/bin/bash

read -p "please input your date (YYYYMMDD ex>20160801)" date2

date_d=$(echo $date2 | grep '[0-9]\{8\}')

if [ "$date_d" == "" ] ; then
	echo "you input the wrong date format...."
	exit 1
fi

declare -i date_dem=`date --date="$date2" +%s`
declare -i date_now=`date +%s`
declare -i date_total_s=$(($date_dem-$date_now))
declare -i date_d=$(($date_total_s/60/60/24))
if [ "$date_total_s" -lt "0" ] ; then
	echo "you had been before: " $(( -1*$date_d)) "ago"
else
	declare -i date_h=$(( $(( $date_total_s-$date_d*60*60*24 )) /60/60 ))
	echo "you will run after $date_d days and $date_h hours"

fi
